A valve timing controller changes a rotation phase between a driving shaft and a driven shaft of an internal combustion engine so as to control opening-and-closing timing of an air intake valve or an exhaust valve driven by the driven shaft. JP-2005-520084A (U.S. Pat. No. 7,484,486 B2) describes a valve timing controller which changes the opening-and-closing timing by rotating a vane rotor relative to a housing through a change in oil pressure of the advance chamber and the retard chamber in the housing. A closing ring covers the housing, and at least one of the housing and the closing ring is made of resin composite material containing resin, inorganic compound, and glass fiber at a predetermined ratio.
Oil in the advance chamber and the retard chamber pushes the housing in the radial direction, and pushes the closing ring and a cover disk which covers another side of the housing in the axial direction. A corner part between the housing and the closing ring or the cover disk receives the stress in the radial direction and the stress in the axial direction, so the stress is concentrated to the corner part. So, the strength required for the housing, especially the corner part, is large.
In a case where the housing is made from resin composite material, if the thickness of the housing is increased to secure the strength, a void may be generated inside the resin, the accuracy of dimension may be lowered by a shrinkage, and the weight becomes large and the material cost becomes high because a large amount of resin is used.
On the other hand, if the thickness of the housing is decreased, the size of the advance chamber and the retard chamber cannot be made larger, and it is necessary to use an expensive resin material which can accept high stress.